Vulnerability CVE-2021-36368


Published: 2022-03-13

Description:
** DISPUTED ** An issue was discovered in OpenSSH before 8.9. If a client is using public-key authentication with agent forwarding but without -oLogLevel=verbose, and an attacker has silently modified the server to support the None authentication option, then the user cannot determine whether FIDO authentication is going to confirm that the user wishes to connect to that server, or that the user wishes to allow that server to connect to a different server on the user's behalf. NOTE: the vendor's position is "this is not an authentication bypass, since nothing is being bypassed."

Type:

CWE-287

(Improper Authentication)

CVSS2 => (AV:N/AC:H/Au:N/C:P/I:N/A:N)

CVSS Base Score
Impact Subscore
Exploitability Subscore
2.6/10
2.9/10
4.9/10
Exploit range
Attack complexity
Authentication
Remote
High
No required
Confidentiality impact
Integrity impact
Availability impact
Partial
None
None
Affected software
Openbsd -> Openssh 

 References:
https://github.com/openssh/openssh-portable/pull/258
https://docs.ssh-mitm.at/trivialauth.html
https://bugzilla.mindrot.org/show_bug.cgi?id=3316
https://www.openssh.com/security.html

Copyright 2024, cxsecurity.com

 

Back to Top